DRILL CASE AND DRILL Russian patent published in 2021 - IPC B23B51/02 

FIELD: drilling.

SUBSTANCE: group of inventions relates to the processing of materials by cutting; it can be used when drilling metals on various machines. Drill case (4) and drill (2) are disclosed. Drill case (4) has axis (10) of rotation and contains central chip groove (20) extending along the perimeter of drill case (4). The cross section of the central chip groove has central line (26) continuing in a plane perpendicular to the axis of rotation and passing through axis (10) of rotation. The cross section of the central chip groove has a depth, if viewed along central line (26), and a width, if viewed perpendicular to central line (26). Cross section of the central chip groove has greatest depth Dp in the range from Dp=0.75 x D/2 to Dp=0.90 x D/2 and greatest width W in the range from W=0.75 x D/2 to W=0.90 x D/2, which continues symmetrically relatively to central line (26).

EFFECT: invention provides increased rigidity of the drill for bending and twisting.

17 cl, 3 dwg